Herbicidal composition comprising nicosulfuron or its salt and S-metolachlor or its salt

ABSTRACT

At present, various herbicidal compositions have been developed and use, but there are a variety of types of weeds to be controlled, and their development lasts for a long period of time. Thus, a herbicidal composition having a broad herbicidal spectrum, having high activity and having a long-lasting effect has been desired. 
     The present invention relates to a herbicidal composition comprising (a) nicosulfuron or its salt and (b) S-metolachlor or its salt. According to the present invention, a herbicidal composition having a broad herbicidal spectrum, having high activity and having a long-lasting effect can be provided.

TECHNICAL FIELD

The present invention relates to a herbicidal composition comprising (a)nicosulfuron or its salt (hereinafter referred to as compound A) and (b)S-metolachlor or its salt (hereinafter referred to as compound B). Thepresent invention further relates to a herbicidal composition whichfurther contains (c) at least one member selected from the groupconsisting of terbuthylazine, mesotrione, prosulfuron, bicyclopyrone andtheir salts (hereinafter referred to as compound C).

BACKGROUND ART

Patent Document 1 discloses a herbicidal composition comprising apyridinesulfonamide compound or its salt and a certain activeingredient. Further, Patent Document 2 discloses a herbicidalcomposition comprising a chloroacetanilide compound of Formula A and atleast one active ingredient selected from the group of substances havingvarious structures. However, Patent Documents 1 and 2 failed tospecifically disclose a specific combination of compound A and compoundB and synergistic effects obtainable when they are combined.

PRIOR ART DOCUMENTS Patent Documents

Patent Document 1: JP-A-2-76803

Patent Document 2: JP-A-11-503438

DISCLOSURE OF INVENTION Technical Problem

At present, many herbicidal compositions have been developed and used,but there are a variety of types of weeds to be controlled, and theirdevelopment lasts for a long period of time. Thus, a herbicidalcomposition having a broad herbicidal spectrum, having high activity andhaving a long-lasting effect has been desired.

Further, compounds A, B and C which are active ingredients in thepresent invention have some problems that the effects are sometimesunsatisfactory to certain weeds, that their residual activities aresometimes poor and the effects are not satisfactorily maintained for acertain period of time, that weeds having lowered sensitivity to certainherbicides emerge, and that satisfactory effects cannot be practicallyachieved depending on applications.

Solution to Problem

The present inventors have conducted a study to solve the above problemsand as a result, have found it possible to obtain an unexpectedlyexcellent herbicidal effect by use of compound A and compound B incombination or as the case requires, use of them and further compound Cin combination, as compared with a case where the respective compoundsare used alone, and thus, the present invention has been accomplished.

That is, the present invention relates to a herbicidal compositioncomprising compound A and compound B, having a synergistic effect (inthis specification, it may sometimes be referred to as a synergisticherbicidal composition). The present invention further relates to such aherbicidal composition further containing compound C having asynergistic effect.

The present invention further relates to a method for controllingundesired plants or inhibiting their growth, which comprises applying aherbicidally effective amount of compound A and a herbicidally effectiveamount of compound B to the undesired plants or to a place where theygrow. The present invention further relates to the method wherein aherbicidally effective amount of compound C is further applied to theundesired plants or to a place where they grow.

Advantageous Effects of Invention

The herbicidal composition of the present invention is capable ofcontrolling a wide range of undesired plants emerging in agriculturalfields or non-agricultural fields. It surprisingly represents asynergistic effect i.e. a herbicidal effect higher than the mereaddition of the respective herbicidal effects of the active ingredients.Such a herbicidal composition of the present invention can be applied ata low dose as compared with a case where the respective activeingredients are applied individually. Thus, it is effective to reducethe environmental load on an area where the composition is applied or asurrounding area thereof.

When the herbicidal activity in a case where two active ingredients arecombined, is larger than the simple sum of the respective herbicidalactivities of the two active ingredients (the expected activity), it iscalled a synergistic effect. The activity expected by the combination oftwo active ingredients can be calculated as follows (Colby S. R.,“Weed”, vol. 15, p. 20-22, 1967).E ₁=α+β−(α×β+100)

In a case where three active ingredients are combined, the activity canbe similarly calculated as follows.E ₂=(α+β+γ)−(αβ+αγ+βγ)/100+(αβγ)/10000where α: growth inhibition rate when treated with x (g/ha) of herbicideX,

β: growth inhibition rate when treated with y (g/ha) of herbicide Y,

γ: growth inhibition rate when treated with z (g/ha) of herbicide Z,

E₁: growth inhibition rate expected when treated with x (g/ha) ofherbicide X and y (g/ha) of herbicide Y.

E₂: growth inhibition rate expected when treated with x (g/ha) ofherbicide X, y (g/ha) of herbicide Y and z (g/ha) of herbicide Z.

That is, when the actual growth inhibition rate (measured value) islarger than the growth inhibition rate by the above calculation(calculated value), the activity by the combination can be regarded asshowing a synergistic effect. The herbicidal composition of the presentinvention shows a synergistic effect when calculated by the aboveformula.

DESCRIPTION OF EMBODIMENTS

As for compound A, nicosulfuron (common name) is2-(4,6-dimethoxypyrimidin-2-ylcarbamoylsulfamoyl)-N,N-dimethylnicotinamide.

As for compound B, S-metolachlor (common name) is a mixture of(aRS,1S)-2-chloro-6′-ethyl-N-(2-methoxy-1-methylethyl)aceto-o-toluidide(80 to 100%) and(aRS,1R)-2-chloro-6′-ethyl-N-(2-methoxy-1-methylethyl)aceto-o-toluidide(20 to 0%).

As for compound C, terbuthylazine (common name) isN²-tert-butyl-6-chloro-N⁴-ethyl-1,3,5-triazine-2,4-diamine, andmesotrione (common name) is2-(4-mesyl-2-nitrobenzoyl)cyclohexane-1,3-dione, and prosulfuron (commonname) is1-(4-methoxy-6-methyl-1,3,5-triazin-2-yl)-3-[2-(3,3,3-trifluoropropyl)phenylsulfonyl]urea,and bicyclopyrone (common name) is4-hydroxy-3-{2-[(2-methoxyethoxy)methyl]-6-(trifluoromethyl)-3-pyridylcarbonyl}bicyclo[3.2.1]oct-3-en-2-one.

The salt included in compound A, compound B and compound C may be anysalt so long as it is agriculturally acceptable. Examples thereofinclude alkali metal salts such as a sodium salt and a potassium salt;alkaline earth metal salts such as a magnesium salt and a calcium salt;ammonium salts such as a monomethylammonium salt, a dimethylammoniumsalt and a triethylammonium salt; inorganic acid salts such as ahydrochloride, a perchlorate, a sulfate and a nitrate, and organic acidsalts such as an acetate and a methanesulfonate.

The mixing ratio of compound A to compound B cannot generally bedefined, as it varies depending upon various conditions such as the typeof the formulation, the weather conditions, and the type and the growthstage of the undesired plants, and is, for example, from 1:1.3 to 1:800,preferably from 1:2.5 to 1:200, more preferably from 1:8 to 1:60,particularly preferably from 1:20 to 1:40 by the weight ratio. Whennicosulfuron and S-metolachlor are mixed in the above mixing ratio offrom 1:20 to 1:40, a particularly excellent effect (for example, asynergistic effect) can be obtained as compared with another mixingratio.

In a case where the composition further contains compound C, the mixingratio of compound A to compound C is, for example, from 1:0.006 to1:400, preferably from 1:0.025 to 1:150 by the weight ratio.

In a case where compound C is terbuthylazine, the mixing ratio ofcompound A to compound C is, for example, from 1:1 to 1:400, preferablyfrom 1:2.5 to 1:150, more preferably from 1:8 to 1:50 by the weightratio. By further mixing terbuthylazine with the combination ofnicosulfuron and S-metolachlor in the above mixing ratio of nicosulfuronto terbuthylazine of from 1:8 to 1:50, a particularly excellent effect(for example, a synergistic effect) will be obtained as compared withanother mixing ratio. Particularly when the mixing ratio of nicosulfuronto S-metolachlor is from 1:20 to 1:40 and the mixing ratio ofnicosulfuron to terbuthylazine is from 1:10 to 1:20, a particularlyexcellent synergistic herbicidal effect against undesired plants,particularly compositae, particularly cocklebur (Xanthium spp.),particularly common cocklebur (Xanthium strumarium L.) will be obtained.

In a case where compound C is mesotrione, the mixing ratio of compound Ato compound C is, for example, from 1:0.05 to 1:100, preferably from1:0.25 to 1:15, more preferably from 1:0.8 to 1:6 by the weight ratio.By further mixing mesotrione with the combination of nicosulfuron andS-metolachlor in the above mixing ratio of nicosulfuron to mesotrione offrom 1:0.8 to 1:6, a particularly excellent effect (for example, asynergistic effect) will be obtained as compared with another mixingratio. Particularly when the mixing ratio of nicosulfuron toS-metolachlor is from 1:20 to 1:40 and the mixing ratio of nicosulfuronto mesotrione is from 1:1.60 to 1:2.40, a particularly excellentsynergistic herbicidal effect against undesired plants, particularlycompositae, particularly cocklebur (Xanthium spp.), particularly commoncocklebur (Xanthium strumarium L.) will be obtained.

In a case where compound C is prosulfuron, the mixing ratio of compoundA to compound C is, for example, from 1:0.006 to 1:15, preferably from1:0.025 to 1:5, more preferably from 1:0.08 to 1:2 by the weight ratio.By further mixing prosulfuron with the combination of nicosulfuron andS-metolachlor in the above mixing ratio of nicosulfuron to prosulfuronof from 1:0.08 to 1:2, a particularly excellent effect (for example, asynergistic effect) will be obtained as compared with another mixingratio. Particularly when the mixing ratio of nicosulfuron toS-metolachlor is from 1:20 to 1:40 and the mixing ratio of nicosulfuronto prosulfuron is from 1:0.1 to 1:1.5, a particularly excellentsynergistic herbicidal effect against undesired plants, particularlycompositae, particularly cocklebur (Xanthium spp.), particularly commoncocklebur (Xanthium strumarium L.) will be obtained.

In a case where compound C is bicyclopyrone, the mixing ratio ofcompound A to compound C is, for example, from 1:0.05 to 1:100,preferably from 1:0.25 to 1:15, more preferably from 1:0.8 to 1:10 bythe weight ratio. By further mixing bicyclopyrone with the combinationof nicosulfuron and S-metolachlor in the above mixing ratio ofnicosulfuron to bicyclopyrone of from 1:0.8 to 1:10, a particularlyexcellent effect (for example, a synergistic effect) will be obtained ascompared with another mixing ratio. Particularly when the mixing ratioof nicosulfuron to S-metolachlor is from 1:1 to 1:300 and the mixingratio of nicosulfuron to bicyclopyrone is from 1:0.1 to 1:20, aparticularly excellent synergistic herbicidal effect against undesiredplants, particularly leguminosae, particularly rattlepod or rattlebox(Crotalaria spp.), particularly sunn-hemp (Crotalaria iuncea L.) will beobtained.

The herbicidally effective amounts of compounds A, B and C cannotgenerally be defined, as they vary depending upon various conditionssuch as the mixing ratio of compound A to compound B, the mixing ratioof compound A, compound B and compound C, the type of the formulation,the weather conditions, and the type and the growth stage of theundesired plants. However, for example, the following may be mentioned.

Compound A is applied in an amount of from 5 to 150 g/ha, preferablyfrom 10 to 100 g/ha, more preferably from 20 to 60 g/ha, particularlypreferably from 30 to 40 g/ha.

Compound B is applied in an amount of from 200 to 4,000 g/ha, preferablyfrom 250 to 2,000 g/ha, more preferably from 500 to 1,200 g/ha,particularly preferably from 800 to 1,200 g/ha.

Compound C is applied in an amount of from 1 to 2,000 g/ha, preferablyfrom 2.5 to 1,500 g/ha.

In a case where compound C is terbuthylazine, compound C is applied inan amount of from 150 to 2,000 g/ha, preferably from 250 to 1,500 g/ha,more preferably from 500 to 1,000 g/ha.

In a case where compound C is mesotrione, compound C is applied in anamount of from 7.5 to 500 g/ha, preferably from 25 to 150 g/ha, morepreferably from 50 to 120 g/ha.

In a case where compound C is prosulfuron, compound C is applied in anamount of from 1 to 75 g/ha, preferably from 2.5 to 50 g/ha, morepreferably from 5 to 25 g/ha.

In a case where compound C is bicyclopyrone, compound C is applied in anamount of from 7.5 to 500 g/ha, preferably from 25 to 150 g/ha, morepreferably from 50 to 150 g/ha.

The herbicidal composition of the present invention may be applied toundesired plants or may be applied to a place where they grow. Further,it may be applied at any time either before or after the emergence ofthe undesired plants. Further, the herbicidal composition of the presentinvention may take various application forms such as soil application,foliar application, irrigation application, and submerged application,and it can be applied to agricultural fields such as upland fields,orchards and paddy fields, and non-cropland such as ridges of fields,fallow fields, play grounds, golf courses, vacant lands, forests,factory sites, railway sides and roadsides.

The herbicidal composition of the present invention can control a widerange of undesired plants such as annual weeds and perennial weeds. Theundesired plants to be controlled by the herbicidal composition of thepresent invention may, for example, be specifically cyperaceae such assedge (Cyperus spp.) (such as purple nutsedge (Cyperus rotundus L.),smallflower umbrella sedge (Cyperus difformis L.), yellow nutsedge(Cyperus esculentus L.) or amur cyperus (Cyperus microiria Steud.)) orspikesedge (Kylling a spp.) (such as green kylling a (Kyllingabrevifolia Rottb. var. leiolepis)); gramineae such as barnyard grass(Echinochloa spp.) (such as bamyardgrass (Echinochloa crus-galli L.),early watergrass (Echinochloa oryzicola vasing.) or Japanese millet(Echinochloa utilis Ohwi et Yabuno)), crabgrass (Digitaria spp.) (suchas summergrass (Digitaria ciliaris (Retz.) Koel), large crabgrass(Digitaria sanguinalis L.), violet crabgrass (Digitaria violascens Link)or Jamaican crabgrass (Digitaria horizontalis Willd.)), goosegrass(Eleusine spp.) (such as goosegrass (Eleusine indica L)), ryegrass(Lolium spp.) (such as italian ryegrass (Lolium multiflorum Lam.)),foxtail (Setaria spp.) (such as green foxtail (Setaria viridis (P.) L.Beauv.) or Japanese bristlegrass (Setaria faberi Herrm.)), sorghum(Sorghum spp.) (such as johnsongrass (Sorghum halepense (L.) Pers.) orshattercane (Sorghum bicolor (L.) Moench.)), oat (Avena spp.) (such aswild oat (Avena fatua L.)), brome (Bromus spp.) (such as drooping brome(Bromus tectorum L.) or japanese brome (Bromus japonicus Thunb.)),meadowgrass (Poa spp.) (such as annual bluegrass (Poa annua L.)),foxtail grass (Alopecurus spp.) (such as blackgrass (Alopecurusmyosuroides Huds.), shortawn foxtail (Alopecurus aequalis Sobol. var.amurensis)), bermudagrass (Cynodon dactylon (L.) Pers.), panic grass(Panicum spp.) (such as guinea grass (Panicum maximum Jacq.) or fallpanicum (Panicum dichotomiflorum (L.) Michx.)), signal grass (Brachiariaspp.) (such as plantain signal grass (Brachiaria plantaginea (LINK)Hitchc.), palisade signal grass (Brachiaria decumbens Stapf) ormauritius signal grass (Brachiaria mutica (Forssk.) Stapf)), paspalum(Paspalum spp.) (such as dallisgrass (Paspalum dilatatum Poir.) orvasey's grass (Paspalum urvillei Steud.)), itchgrass (Rottboellia spp.)(such as itchgrass (Rottboellia cochinchinensis (LOUR.) W. D. CLAYTON)),sandbur (Cenchrus spp.) (such as southern sandbur (Cenchrus echinatusL.)) or wildrye (Agropyron spp.) (such as quackgrass (Agropyron repens(L.) P. Beauv.)); scrophulariaceae such as persian speedwell (Veronicapersica Poir.) or corn speedwell (Veronica arvensis L.); compositae suchas beggar ticks (Bidens spp.) (such as hairy beggarticks (Bidens pilosaL.), devils berggarticks (Bidens frondosa L.) or Bidens biternata(Lour.) Merr. et Sherff, beggarticks (Bidens subalternans DC.)),dandelion (Taraxacum spp.) (such as dandelion (Taraxacum officinaleWeber)), horseweed (Conyza spp.) (such as canadian horseweed (Conyzacanadensis (L.) Cronquist) or hairy fleabane (Conyza bonariensis (L.)Cronq.)), cocklebur (Xanthium spp.) (such as common cocklebur (Xanthiumstrumarium L.)), ragweed (Ambrosia spp.) (such as annual ragweed(Ambrosia artemisiifolia L.)), ragwort (Senecio spp.) (such asold-man-in-the-spring (Senecio vulgaris L.)), gallant soldier (Galinsogaspp.) (such as shaggy soldier (Galinsoga quadriradiata Cav.)),sowthistle (Sonchus spp.) (such as field sowthistle (Sonchus arvensisL.)), or thistle (Cirsium spp.) (such as canada thistle (Cirsiumarvense, (L.) Scop.)); leguminosae such as rattlepod or rattlebox(Crotalaria spp.) (such as sunn-hemp (Crotalaria iuncea L.)), poisonbean (Sesbania spp.) (such as rostrate sesbania (Sesbania rostrataBremek. & Oberm.) or sesbania pea (Sesbania cannabina (Retz.) Pers.)),korean lespedeza (Kummerowia stipulacea (Maxim.) Makino) or white clover(Trifolium repens L.)); caryophyllaceae such as sticky chickweed(Cerastium qlomeratum Thuill.), or starwort (Stellaria spp.) (such ascommon chickweed (Stellaria media L.)); euphorbiaceae such as gardenspurge (Euphorbia hirta L.), threeseeded copperleaf (Acalypha australisL.) or fireplant (Euphorbia heterophylla L.); plantaginaceae such asasiatic plantain (Plantago asiatica L.); oxalidaceae such as creepingwoodsorrel (Oxalis corniculata L.); apiaceae such as lawn pennywort(Hydrocotyle sibthorpioides Lam.); violaceae such as violet (Violamandshurica W. Becker); iridaceae such as blue-eyedgrass (Sisyrinchiumrosulatum Bicknell); geraniaceae such as carolina geranium (Geraniumcarolinianum L.); labiatae such as purple deadnettle (Lamium purpureumL.) or henbit (Lamium amplexicaule L.); malvaceae such as velvetleaf(Abutilon theophrasti MEDIC.) or prickly sida (Sida spinosa L.);convolvulaceae such as ivy-leaved morningglory (Ipomoea hederacea (L.)Jacq.), common morningglory (Ipomoea purpurea ROTH), cypressvinemorningglory (Ipomoea quamoclit L.), Ipomoea grandifolia (DAMMERMANN)O'DONNELL, hairy merremia (Merremia aeqyptia (L.) URBAN) or fieldbindweed (Convolvulus arvensis L.); chenopodiaceae such as goosefoot(Chenopodium spp.) (such as common lambsquarters (Chenopodium albumL.)); portulacaceae such as common purslane (Portulaca oleracea L.);amaranthaceae such as pigweed (Amaranthus spp.) (such as prostratepigweed (Amaranthus blitoides S. Wats.), livid amaranth (Amaranthuslividus L.), purple amaranth (Amaranthus blitum L.), smooth pigweed(Amaranthus hybridus L., Amaranthus patulus Bertol.), powell amaranth(Amaranthus powellii S. Wats.), slender amaranth (Amaranthus viridisL.), palmer amaranth (Amaranthus palmeri S. Wats.), redroot pigweed(Amaranthus retroflexus L.), tall waterhemp (Amaranthus tuberculatus(Moq.) Sauer.), common waterhemp (Amaranthus tamariscinus Nutt.), thornyamaranth (Amaranthus spinosus L)), ataco (Amaranthus quitensis Kunth.)or roughfruit amaranth (Amaranthus rudis Sauer.)); solanaceae such asnightshade (Solanum spp.) (such as black nightshade (Solanum niqrumL.)); polygonaceae such as knotweed (Polygonum spp.) (such as spottedknotweed (Polygonum lapathifolium L.) or green smartweed (Polygonumscabrum MOENCH)); cruciferae such as flexuous bittercress (Cardamineflexuosa WITH.), or mustard (Sinapis spp.) (such as Charlock (Sinapisarvensis L.)); cucurbitaceae such as burcucumber (Sicyos angulatus L.);commelinaceae such as common dayflower (Commelina communis L.); rosaceaesuch as mock strawberry (Duchesnea chrysantha (Zoll. et Mor.) Miq.);molluqinacea such as carpetweed (Mollugo verticillata L.); or rubiaceaesuch as false cleavers (Galium spurium var. echinospermon (Wallr.)Hayek) or stickywilly (Galium aparine L.).

The herbicidal composition of the present invention is very useful inpractical application. For example, the following cases may bementioned.

(1) It has a remarkable synergistic effect, and has a favorableherbicidal activity even if the doses of the respective compounds A, Band C are small, and accordingly the impact on the surroundingenvironment can be suppressed.

(2) It can control annual and perennial gramineae such as barnyard grass(Echinochloa spp.), crabgrass (Digitaria spp.), foxtail (Setaria spp.),meadowgrass (Poa spp.), oat (Avena spp.), wildrye (Agropyron spp.),foxtail grass (Alopecurus spp.), goosegrass (Eleusine spp.), itchgrass(Rottboellia spp.), sorghum (Sorghum spp.) and panic grass (Panicumspp.), which are problematic as noxious weeds in agricultural fields,particularly corn fields.

Noxious weeds may, for example, be weeds which can hardly be controlledby existing herbicides, weeds which are hardly eradicated by spread ofrhizomes, or weeds having high reproductivity such that even when theirroots are cut e.g. by plowing, they reproduce from part of their roots.They are not only hardly controlled, but make it difficult to harvestcrops. In addition, if they are included in the gathered crops, they maycause bad odor in silage, solanine or the like contained in the weedswill lower palatability, or domestic animals may be poisoned withalkaloids or the like contained in the weeds. Accordingly, such weedscause serious damages to farmers.

(3) It has a high herbicidal activity also against weeds in late leafstage, such as weeds in 5-leaf stage to heading stage, and such isparticularly remarkable for gramineae. In a case where compounds A, Band C are applied alone, the formulations are applied usually by thetime of tillering. For example, in the case of summergrass (Digitariaciliaris (Retz.) Koel), large crabgrass (Digitaria sanguinalis L.), theformulations are usually applied no later than about 4-leaf stage.

(4) It has a favorable herbicidal activity against gramineae and broadleaf weeds either by foliar application or soil application. It has along lasting residual activity particularly against gramineae,polygonaceae and compositae.

(5) It has a high herbicidal activity against weeds having loweredsensitivity to herbicides, such as cyperaceae, amaranthaceae, compositaeand gramineae. The weeds having lowered sensitivity to herbicides may beweeds having lowered sensitivity to ALS inhibitors, including weedshaving lowered sensitivity to sulfonylurea compounds.

The herbicidal composition of the present invention may contain otherherbicidally effective component in addition to the above activeingredients, without departing from the intention and the scope of thepresent invention, whereby the range of weeds to be controlled, the timeof application of the composition, the herbicidal activities, etc. maybe improved to preferred directions. Other herbicidally effectivecomponent includes, for example, the following compounds (by commonnames including ones under application for approval by ISO, or testcodes; common names under application for approval by ISO mean commonnames before approval by ISO (International Organization forStandardization)). Even when not specifically mentioned here, in a casewhere such compounds have salts, alkyl esters, hydrates, differentcrystal forms, various structural isomers, etc., they are, of course,all included.

(1) Those which are believed to exhibit herbicidal effects by disturbinghormone activities of plants, such as a phenoxy type such as 2,4-D,2,4-D-butotyl, 2,4-D-butyl, 2,4-D-dimethylammonium, 2,4-D-diolamine,2,4-D-ethyl, 2,4-D-2-ethylhexyl, 2,4-D-isobutyl, 2,4-D-isoctyl,2,4-D-isopropyl, 2,4-D-isopropylammonium, 2,4-D-sodium,2,4-D-isopropanolammonium, 2,4-D-trolamine, 2,4-DB, 2,4-DB-butyl,2,4-DB-dimethylammonium, 2,4-DB-isoctyl, 2,4-DB-potassium,2,4-DB-sodium, dichlorprop, dichlorprop-butotyl,dichlorprop-dimethylammonium, dichlorprop-isoctyl,dichlorprop-potassium, dichlorprop-P, dichlorprop-P-dimethylammonium,dichlorprop-P-potassium, dichlorprop-P-sodium, MCPA, MCPA-butotyl,MCPA-dimethylammonium, MCPA-2-ethylhexyl, MCPA-potassium, MCPA-sodium,MCPA-thioethyl, MCPB, MCPB-ethyl, MCPB-sodium, mecoprop,mecoprop-butotyl, mecoprop-sodium, mecoprop-P, mecoprop-P-butotyl,mecoprop-P-dimethylammonium, mecoprop-P-2-ethylhexyl,mecoprop-P-potassium, naproanilide or clomeprop; an aromatic carboxylicacid type such as 2,3,6-TBA, dicamba, dicamba-butotyl,dicamba-diglycolamine, dicamba-dimethylammonium, dicamba-diolamine,dicamba-isopropylammonium, dicamba-potassium, dicamba-sodium,dichlobenil, picloram, picloram-dimethylammonium, picloram-isoctyl,picloram-potassium, picloram-triisopropanolammonium,picloram-triisopropylammonium, picloram-trolamine, triclopyr,triclopyr-butotyl, triclopyr-triethylammonium, clopyralid,clopyralid-olamine, clopyralid-potassium,clopyralid-triisopropanolammonium or aminopyralid; and others such asnaptalam, naptalam-sodium, benazolin, benazolin-ethyl, quinclorac,quinmerac, diflufenzopyr, diflufenzopyr-sodium, fluoroxypyr,fluoroxypyr-2-butoxy-1-methylethyl, fluoroxypyr-meptyl, chlorflurenol,chlorflurenol-methyl, aminocyclopyrachlor, aminocyclopyrachlor-methyl oraminocyclopyrachlor-potassium.

(2) Those which are believed to exhibit herbicidal effects by inhibitingphotosynthesis of plants, such as a urea type such as chlorotoluron,diuron, fluometuron, linuron, isoproturon, metobenzuron, tebuthiuron,dimefuron, isouron, karbutilate, methabenzthiazuron, metoxuron,monolinuron, neburon, siduron, terbumeton, trietazine or metobromuron; atriazine type such as simazine, atrazine, atratone, simetryn, prometryn,dimethametryn, hexazinone, metribuzin, terbuthylazine, cyanazine,ametryn, cybutryne, triaziflam, indaziflam, terbutryn, propazine,metamitron or prometon; a uracil type such as bromacil,bromacyl-lithium, lenacil or terbacil; an anilide type such as propanilor cypromid; a carbamate type such as swep, desmedipham or phenmedipham;a hydroxybenzonitrile type such as bromoxynil, bromoxynil-octanoate,bromoxynil-heptanoate, ioxynil, ioxynil-octanoate, ioxynil-potassium orioxynil-sodium; and others such as pyridate, bentazone,bentazone-sodium, amicarbazone, methazole or pentanochior.

(3) Quaternary ammonium salt type such as paraquat or diquat, which isbelieved to be converted to free radicals by itself to form activeoxygen in the plant body and shows rapid herbicidal efficacy.

(4) Those which are believed to exhibit herbicidal effects by inhibitingchlorophyll biosynthesis of plants and abnormally accumulating aphotosensitizing peroxide substance in the plant body, such as adiphenylether type such as nitrofen, chlomethoxyfen, bifenox,acifluorfen, acifluorfen-sodium, fomesafen, fomesafen-sodium,oxyfluorfen, lactofen, aclonifen, ethoxyfen-ethyl (HC-252),fluoroglycofen-ethyl or fluoroglycofen; a cyclic imide type such aschlorphthalim, flumioxazin, flumiclorac, flumiclorac-pentyl,cinidon-ethyl, fluthiacet or fluthiacet-methyl; and others such asoxadiargyl, oxadiazon, sulfentrazone, carfentrazone-ethyl, thidiazimin,pentoxazone, azafenidin, isopropazole, pyraflufen-ethyl, benzfendizone,butafenacil, saflufenacil, flupoxam, fluazolate, profluazol, pyraclonil,flufenpyr-ethyl, bencarbazone orethyl[3-(2-chloro-4-fluoro-5-(3-methyl-2,6-dioxo-4-trifluoromethyl-3,6-dihydro-2H-pyrimidin-1-yl)phenoxy)pyridin-2-yloxy]acetate(SYN-523).

(5) Those which are believed to exhibit herbicidal effects characterizedby bleaching activities by inhibiting chromogenesis of plants such ascarotenoids, such as a pyridazinone type such as norfiurazon,chloridazon or metflurazon; a pyrazole type such as pyrazolynate,pyrazoxyfen, benzofenap, topramezone or pyrasulfotole; and others suchas amitrole, fluridone, flurtamone, diflufenican, methoxyphenone,clomazone, sulcotrione, mesotrione, tembotrione, tefuryltrione(AVH-301), bicyclopyrone, isoxaflutole, difenzoquat,difenzoquat-metilsulfate, isoxachlortole, benzobicyclon, picolinafen orbeflubutamid.

(6) Those which exhibit strong herbicidal effects specifically togramineous plants, such as an aryloxyphenoxypropionic acid type such asdiclofop-methyl, diclofop, pyriphenop-sodium, fluazifop-butyl,fluazifop, fluazifop-P, fluazifop-P-butyl, haloxyfop-methyl, haloxyfop,haloxyfop-etotyl, haloxyfop-P, haloxyfop-P-methyl, quizalofop-ethyl,quizalofop-P, quizalofop-P-ethyl, quizalofop-P-tefuryl, cyhalofop-butyl,fenoxaprop-ethyl, fenoxaprop-P, fenoxaprop-P-ethyl, metamifop-propyl,metamifop, clodinafop-propargyl, clodinafop or propaquizafop; acyclohexanedione type such as alloxydim-sodium, alloxydim, clethodim,sethoxydim, tralkoxydim, butroxydim, tepraloxydim, profoxydim orcycloxydim; and others such as flamprop-M-methyl, flamprop-M orflamprop-M-isopropyl.

(7) Those which are believed to exhibit herbicidal effects by inhibitingan amino acid biosynthesis of plants, such as a sulfonylurea type suchas chlorimuron-ethyl, chlorimuron, sulfometuron-methyl, sulfometuron,primisulfuron-methyl, primisulfuron, bensulfuron-methyl, bensulfuron,chiorsulfuron, metsulfuron-methyl, metsulfuron, cinosulfuron,pyrazosulfuron-ethyl, pyrazosulfuron, azimsulfuron, rimsulfuron,imazosulfuron, cyclosulfamuron, prosulfuron,flupyrsulfuron-methyl-sodium, flupyrsulfuron, triflusulfuron-methyl,triflusulfuron, halosulfuron-methyl, halosulfuron,thifensulfuron-methyl, thifensulfuron, ethoxysulfuron, oxasulfuron,ethametsulfuron, ethametsulfuron-methyl, iodosulfuron,iodosulfuron-methyl-sodium, sulfosulfuron, triasulfuron,tribenuron-methyl, tribenuron, tritosulfuron, foramsulfuron,trifloxysulfuron, trifloxysulfuron-sodium, mesosulfuron-methyl,mesosulfuron, orthosulfamuron, flucetosulfuron, amidosulfuron,propyrisulfuron (TH-547), metazosulfuron, iofensulfuron, or a compounddisclosed in the claim of WO2005092104; a triazolopyrimidinesulfonamidetype such as flumetsulam, metosulam, diclosulam, cloransulam-methyl,florasulam, penoxsulam or pyroxsulam; an imidazolinone type such asimazapyr, imazapyr-isopropylammonium, imazethapyr, imazethapyr-ammonium,imazaquin, imazaquin-ammonium, imazamox, imazamox-ammonium,imazamethabenz, imazamethabenz-methyl or imazapic; apyrimidinylsalicylic acid type such as pyrithiobac-sodium,bispyribac-sodium, pyriminobac-methyl, pyribenzoxim, pyriftalid,pyrimisulfan or triafamone; a sulfonylaminocarbonyltriazolinone typesuch as flucarbazone, flucarbazone-sodium, propoxycarbazone-sodium,propoxycarbazone or thiencarbazone; and others such as glyphosate,glyphosate-sodium, glyphosate-potassium, glyphosate-ammonium,glyphosate-diammonium, glyphosate-isopropylammonium,glyphosate-trimesium, glyphosate-sesquisodium, glufosinate,glufosinate-ammonium, glufosinate-P, glufosinate-P-ammonium,glufosinate-P-sodium, bilanafos, bilanafos-sodium or cinmethylin.

(8) Those which are believed to exhibit herbicidal effects by inhibitingcell mitoses of plants, such as a dinitroaniline type such astrifluralin, oryzalin, nitralin, pendimethalin, ethalfluralin,benfluralin, prodiamine, butralin or dinitramine; an amide type such asbensulide, napropamide, propyzamide or pronamide; an organic phosphorustype such as amiprofos-methyl, butamifos, anilofos or piperophos; aphenyl carbamate type such as propham, chlorpropham, barban orcarbetamide; a cumylamine type such as daimuron, cumyluron, bromobutideor methyldymron; and others such as asulam, asulam-sodium, dithiopyr,thiazopyr, chlorthal-dimethyl, chiorthal or diphenamid.

(9) Those which are believed to exhibit herbicidal effects by inhibitingprotein biosynthesis or lipid biosynthesis of plants, such as achloroacetamide type such as alachlor, metazachlor, butachlor,pretilachlor, metolachlor, thenylchlor, pethoxamid, acetochlor,propachlor, dimethenamid, dimethenamid-P, propisochloror dimethachlor; athiocarbamate type such as molinate, dimepiperate, pyributicarb, EPTC,butylate, vernolate, pebulate, cycloate, prosulfocarb, esprocarb,thiobencarb, diallate, tri-allate or orbencarb; and others such asetobenzanid, mefenacet, flufenacet, tridiphane, cafenstrole,fentrazamide, oxaziclomefone, indanofan, benfuresate, pyroxasulfone,fenoxasulfone, dalapon, dalapon-sodium, TCA-sodium or trichloroaceticacid.

(10) MSMA, DSMA, CMA, endothall, endothall-dipotassium,endothall-sodium, endothall-mono(N,N-dimethylalkylammonium),ethofumesate, sodium chlorate, pelargonic acid (nonanoic acid),fosamine, fosamine-ammonium, pinoxaden, ipfencarbazone (HOK-201),aclolein, ammonium sulfamate, borax, chloroacetic acid, sodiumchloroacete, cyanamide, methylarsonic acid, dimethylarsinic acid, sodiumdimethylarsinate, dinoterb, dinoterb-ammonium, dinoterb-diolamine,dinoterb-acetate, DNOC, ferrous sulfate, flupropanate,flupropanate-sodium, isoxaben, mefluidide, mefluidide-diolamine, metam,metam-ammonium, metam-potassium, metam-sodium, methyl isothiocyanate,pentachlorophenol, sodium pentachlorophenoxide, pentachlorophenollaurate, quinoclamine, sulfuric acid, urea sulfate, methiozolin(MRC-01), etc.

(11) Those which are believed to exhibit herbicidal effects by beingparasitic on plants, such as Xanthomonas campestris, Epicoccosirusnematosorus, Epicoccosirus nematosperus, Exserohilum monoseras orDrechsrela monoceras.

The herbicidal composition of the present invention may be prepared bymixing compound A, compound B and compound C, as active ingredients,with various agricultural additives in accordance with conventionalformulation methods for agricultural chemicals, and applied in variousformulations such as dusts, granules, water dispersible granules,wettable powders, tablets, pills, capsules (including a formulationpackaged by a water soluble film), water-based suspensions, oil-basedsuspensions, microemulsions, suspoemulsions, water soluble powders,emulsifiable concentrates, soluble concentrates or pastes. It may beformed into any formulation which is commonly used in this field, solong as the object of the present invention is thereby met.

At the time of the formulation, compound A, compound B and compound Cmay be mixed together for the formulation, or they may be separatelyformulated.

The additives to be used for the formulation include, for example, asolid carrier such as kaolinite, sericite, diatomaceous earth, slakedlime, calcium carbonate, talc, white carbon, kaoline, bentonite, clay,sodium carbonate, sodium bicarbonate, mirabilite, zeolite or starch; asolvent such as water, toluene, xylene, solvent naphtha, dioxane,dimethylsulfoxide, N,N-dimethylformamide, dimethylacetamide,N-methyl-2-pyrrolidone or an alcohol; an anionic surfactant such as asalt of fatty acid, a benzoate, a polycarboxylate, a salt ofalkylsulfuric acid ester, an alkyl sulfate, an alkylaryl sulfate, analkyl diglycol ether sulfate, a salt of alcohol sulfuric acid ester, analkyl sulfonate, an alkylaryl sulfonate, an aryl sulfonate, a ligninsulfonate, an alkyldiphenylether disulfonate, a polystyrene sulfonate, asalt of alkylphosphoric acid ester, an alkylaryl phosphate, a styrylarylphosphate, a salt of polyoxyethylene alkyl ether sulfuric acid ester, apolyoxyethylene alkylaryl ether sulfate, a salt of polyoxyethylenealkylaryl ether sulfuric acid ester, a polyoxyethylene alkyl etherphosphate, a salt of polyoxyethylene alkylaryl phosphoric acid ester, asalt of polyoxyethylene aryl ether phosphoric acid ester, a naphthalenesulfonic acid condensed with formaldehyde or a salt of alkylnaphthalenesulfonic acid condensed with formaldehyde; a nonionic surfactant such asa sorbitan fatty acid ester, a glycerin fatty acid ester, a fatty acidpolyglyceride, a fatty acid alcohol polyglycol ether, acetylene glycol,acetylene alcohol, an oxyalkylene block polymer, a polyoxyethylene alkylether, a polyoxyethylene alkylaryl ether, a polyoxyethylene styrylarylether, a polyoxyethylene glycol alkyl ether, polyethylene glycol, apolyoxyethylene fatty acid ester, a polyoxyethylene sorbitan fatty acidester, a polyoxyethylene glycerin fatty acid ester, a polyoxyethylenehydrogenated castor oil or a polyoxypropylene fatty acid ester; and avegetable oil or mineral oil such as olive oil, kapok oil, castor oil,palm oil, camellia oil, coconut oil, sesame oil, corn oil, rice branoil, peanut oil, cottonseed oil, soybean oil, rapeseed oil, linseed oil,tung oil or liquid paraffins. These additives may suitably be selectedfor use alone or in combination as a mixture of two or more of them, solong as the object of the present invention is met. Further, additivesother than the above-mentioned may be suitably selected for use amongthose known in this field. For example, various additives commonly used,such as a filler, a thickener, an anti-settling agent, an anti-freezingagent, a dispersion stabilizer, a safener, an anti-mold agent, a bubbleagent, a disintegrator and a binder, may be used. The mix ratio byweight of the active ingredient to such various additives may be from0.001:99.999 to 95:5, preferably from 0.005:99.995 to 90:10.

As a method of applying the herbicidal composition of the presentinvention, a proper method can be employed among various methodsdepending upon various conditions such as the application site, the typeof the formulation, and the type and the growth stage of the undesiredplants to be controlled, and for example, the following methods may bementioned.

(1-1) Compound A and compound B are separately formulated, and theformulations are applied as they are, or they are diluted topredetermined concentrations with e.g. water as the case requires, andas the case requires, a spreader (such as a surfactant, a vegetable oilor a mineral oil) is added for application.

(1-2) Compound A and compound B are separately formulated, and theformulations are mixed when diluted to a predetermined concentrationwith e.g. water, and as the case requires, a spreader (such as asurfactant, a vegetable oil or a mineral oil) is added for application.

(1-3) Compound A and compound B are formulated together, and theformulation is applied as it is, or the formulation is diluted to apredetermined concentration with e.g. water as the case requires, and asthe case requires, a spreader (such as a surfactant, a vegetable oil ora mineral oil) is added for application.

(2-1) Compound A, compound B and compound C are separately formulated,and the formulations are applied as they are, or they are diluted topredetermined concentrations with e.g. water as the case requires, andas the case requires, a spreader (such as a surfactant, a vegetable oilor a mineral oil) is added for application.

(2-2) Compound A and compound B are formulated together, and compound Cis formulated, and the formulations are applied as they are or dilutedto predetermined concentrations with e.g. water as the case requires,and as the case requires, a spreader (such as a surfactant, a vegetableoil or a mineral oil) is added for application.

(2-3) Compound A and compound C are formulated together, and compound Bis formulated, and the formulations are applied as they are or dilutedto predetermined concentrations with e.g. water as the case requires,and as the case requires, a spreader (such as a surfactant, a vegetableoil or a mineral oil) is added for application.

(2-4) Compound B and compound C are formulated together, and compound Ais formulated, and the formulations are applied as they are or dilutedto predetermined concentrations with e.g. water as the case requires,and as the case requires, a spreader (such as a surfactant, a vegetableoil or a mineral oil) is added for application.

(2-5) Compound A, compound B and compound C are formulated together, andthe formulation is applied as it is or diluted to a predeterminedconcentration with e.g. water as the case requires, and as the caserequires, a spreader (such as a surfactant, a vegetable oil or a mineraloil) is added for application.

In the above application methods (1-1), (1-2) and (2-1) to (2-4), therespective formulations may be mixed when diluted to a predeterminedconcentration with e.g. water so that they are applied to plants to becontrolled simultaneously, or they may be applied continuously or withan appropriate interval. In order to obtain effects of the presentinvention more effectively, it is preferred to apply compound A andcompound B simultaneously or to apply compound A, compound B andcompound C simultaneously.

Preferred embodiments of the present invention will be described below,but the present invention is by no means restricted thereto.

(1) A herbicidal composition comprising, as active ingredients, (a)nicosulfuron or its salt and (b) S-metolachlor or its salt.

(2) A method for controlling undesired plants or inhibiting theirgrowth, which comprises applying a herbicidally effective amount of (a)nicosulfuron or its salt and a herbicidally effective amount of (b)S-metolachlor or its salt, to the undesired plants or to a place wherethey grow.

(3) The herbicidal composition according to (1), wherein the weightratio of (a) to (b) is within a range of from 1:1.3 to 1:800.

(4) The method according to (2), wherein (a) is applied in an amount offrom 5 to 150 g/ha, and (b) is applied in an amount of from 200 to 4,000g/ha.

(5) The herbicidal composition according to (1), which further contains,as an active ingredient, (c) at least one member selected from the groupconsisting of terbuthylazine, mesotrione, prosulfuron, bicyclopyrone andtheir salts.

(6) The method according to (2), wherein a herbicidally effective amountof (c) at least one member selected from the group consisting ofterbuthylazine, mesotrione, prosulfuron, bicyclopyrone and their saltsis further applied to the undesired plants or to a place where theygrow.

(7) The method according to (2) or (6), wherein the undesired plants areundesired plants having lowered sensitivity to herbicides.

(8) The method according to (2) or (6), wherein the undesired plants areplants having lowered sensitivity to ALS inhibitors.

(9) The method according to (2) or (6), wherein by application of theherbicidally active ingredients to the undesired plants or to a placewhere they grow, they are controlled or their growth is inhibited overat least 40 days, preferably at least 60 days, after the application.

(10) The method according to (2) or (6), wherein by application of theherbicidally active ingredients to pramineae or polygonaceae or to aplace where they grow, they are controlled or their growth is inhibitedover at least 40 days, preferably at least 60 days, after theapplication.

(11) The method according to (2) or (6), wherein the undesired plantsare undesired plants in 7- or later leaf stage.

(12) The herbicidal composition according to (5), wherein the weightratio of (a) to (b) is within a range of from 1:1.3 to 1:800, and theweight ratio of (a) to (c) is within a range of from 1:0.006 to 1:400.

(13) The method according to (6), wherein (a) is applied in an amount offrom 5 to 150 g/ha, (b) is applied in an amount of from 200 to 4,000g/ha, and (c) is applied in an amount of from 1 to 2,000 g/ha.

(14) The method according to (2) or (6), wherein the undesired plantsare weeds having lowered sensitivity to sulfonylurea compounds.

(15) The herbicidal composition according to (5), wherein (c) isterbuthylazine or its salt, and the weight ratio of (a) to (b) is withina range of from 1:20 to 1:40, and the weight ratio of (a) to (c) iswithin a range of from 1:10 to 1:20.

(16) The method according to (14), wherein the weeds having loweredsensitivity to sulfonylurea compounds are cyperaceae, amaranthaceae,compositae or gramineae.

(17) The method according to (14), wherein the weeds having loweredsensitivity to sulfonylurea compounds are cyperaceae or gramineae.

(18) The method according to (2) or (6), wherein the undesired plantsare compositae or gramineae.

(19) The method according to (16) or (18), wherein the undesired plants(or weeds) are compositae, and the compositae is at least one memberselected from the group consisting of cocklebur (Xanthium spp.), beggarticks (Bidens spp.), ragweed (Ambrosia spp.), horseweed (Conyza spp.),gallant soldier (Galinsoga spp.), sowthistle (Sonchus spp.), dandelion(Taraxacum spp.), thistle (Cirsium spp.) and ragwort (Senecio spp.).

(20) The method according to (16) or (18), wherein the undesired plants(or weeds) are gramineae, and the gramineae is at least one memberselected from the group consisting of barnyard grass (Echinochloa spp.),signal grass (Brachiaria spp.), panic grass (Panicum spp.), crabgrass(Digitaria spp.), sorghum (Sorghum spp.), foxtail (Setaria spp.),meadowgrass (Poa spp.), oat (Avena spp.), wildrye (Agropyron spp.),foxtail grass (Alopecurus spp.), goosegrass (Eleusine spp.), ryegrass(Lolium spp.), sandbur (Cenchrus spp.), brome (Bromus spp.) anditchgrass (Rottboellia spp.).

(21) The method according to (2) or (6), wherein the undesired plantsare at least one member selected from the group consisting of commoncocklebur (Xanthium strumarium L.), wild oat (Avena fatua L.),barnyardgrass (Echinochloa crus-galli L.), early watergrass (Echinochloaoryzicola vasing.), Japanese millet (Echinochloa utilis Ohwi et Yabuno),summergrass (Digitaria ciliaris (Retz.) Koel), large crabgrass(Digitaria sanquinalis L.), violet crabgrass (Digitaria violascensLink), Jamaican crabgrass (Digitaria horizontalis Willd.), sunn-hemp(Crotalaria juncea L.), green kylling a (Kyllinga brevifolia Rottb. var.leiolepis), green foxtail (Setaria viridis (P.) L. Beauv.), Japanesebristlegrass (Setaria faberi Herrm.), spotted knotweed (Polygonumlapathifolium L.), green smartweed (Polygonum scabrum MOENCH) and annualbluegrass (Poa annua L.).

(22) The method according to (2) or (6), wherein the undesired plantsare at least one member selected from the group consisting of commoncocklebur (Xanthium strumarium L.), wild oat (Avena fatua L.), Japanesemillet (Echinochloa utilis Ohwi et Yabuno), summergrass (Digitariaciliaris (Retz.) Koel), large crabgrass (Digitaria sanquinalis L.),sunn-hemp (Crotalaria juncea L.), green kylling a (Kyllinga brevifoliaRottb. var. leiolepis), Japanese bristlegrass (Setaria faberi Herrm.),spotted knotweed (Polygonum lapathifolium L.) and annual bluegrass (Poaannua L.).

(23) The herbicidal composition according to (1), which furthercontains, as an active ingredient, (c) terbuthylazine or its salt.

(24) The herbicidal composition according to (1), which furthercontains, as an active ingredient, (c) mesotrione or its salt.

(25) The herbicidal composition according to (1), which furthercontains, as an active ingredient, (c) prosulfuron or its salt.

(26) The herbicidal composition according to (1), which furthercontains, as an active ingredient, (c) bicyclopyrone or its salt.

(27) A herbicidal composition comprising (a) and (b), to be used incombination with (c).

(28) A herbicidal composition comprising (a) and (c), to be used incombination with (b).

(29) A herbicidal composition comprising (b) and (c), to be used incombination with (a).

(30) Use of (a), (b) and (c) in combination, to control undesired plantsor to inhibit their growth.

(31) Use of a composition comprising (a) and (b), and component (c), incombination, to control undesired plants or to inhibit their growth.

(32) Use of a composition comprising (a) and (c), and component (b), incombination, to control undesired plants or to inhibit their growth.

(33) Use of a composition comprising (b) and (c), and component (a), incombination, to control undesired plants or to inhibit their growth.

(34) The use in combination according to (27) to (33), wherein (c) isterbuthylazine or its salt.

(35) The use in combination according to (27) to (34), to controlundesired plants having lowered sensitivity to herbicides or to inhibittheir growth.

(36) The use in combination according to (27) to (35), wherein theundesired plants are at least one member selected from the groupconsisting of common cocklebur (Xanthium strumarium L.), wild oat (Avenafatua L.), barnyardgrass (Echinochloa crus-galli L.), early watergrass(Echinochloa oryzicola vasing.), Japanese millet (Echinochloa utilisOhwi et Yabuno), summergrass (Digitaria ciliaris (Retz.) Koel), largecrabgrass (Digitaria sanguinalis L.), violet crabgrass (Digitariaviolascens Link), Jamaican crabgrass (Digitaria horizontalis Willd.),sunn-hemp (Crotalaria iuncea L.), green kylling a (Kylling a brevifoliaRottb. var. leiolepis), green foxtail (Setaria viridis (P.) L. Beauv.),Japanese bristlegrass (Setaria faberi Herrm.), spotted knotweed(Polygonum lapathifolium L.), green smartweed (Polygonum scabrum MOENCH)and annual bluegrass (Poa annua L.).

EXAMPLES

Now, the present invention will be described in further detail withreference to Examples. However, the present invention is by no meansrestricted to such specific Examples.

Test Example 1

Upland field soil was put into a 1/1,000,000 ha pot, and seeds of commoncocklebur (Xanthium strumarium L.) were sown. When the common cockleburreached 4.3 to 4.8-leaf stage, predetermined amounts of SC agentcontaining nicosulfuron as an active ingredient (tradename: ONEHOPENYUZAI, manufactured by Ishihara Sangyo Kaisha, Ltd.), EC agentcontaining S-metolachlor as an active ingredient (tradename: Dual Gold,manufactured by Syngenta Crop Protection AG), SC agent containingterbuthylazine as an active ingredient (tradename: Click, manufacturedby BASF), SC agent containing mesotrione as an active ingredient(tradename: Callisto, manufactured by Syngenta Crop Protection AG) andWG agent containing prosulfuron as an active ingredient (tradename:Peak, manufactured by Syngenta Crop Protection AG) were diluted withwater in an amount corresponding to 1,000 L/ha, and applied for foliartreatment by a small sprayer.

On the 22nd day after treatment, the state of growth of the commoncocklebur was visually observed to determine the growth inhibition ratein accordance with the following evaluation standard. The growthinhibition rate (%) (measured value) and the growth inhibition rate (%)(calculated value) calculated by the Colby's formula are shown in Table1.

Growth inhibition rate (%)=0 (equivalent to the non-treated area) to 100(complete kill)

TABLE 1 Growth inhibition rate (%) of common cocklebur Compound Dose(g/ha) Measured value Calculated value Nicosulfuron 30 0 — S-metolachlor1000 0 — Terbuthylazine 500 10 — Mesotrione 50 0 — Prosulfuron 15 88 —Nicosulfuron +  30 + 1000 + 500 70 10 S-metolachlor + TerbuthylazineNicosulfuron + 30 + 1000 + 50 30  0 S-metolachlor + MesotrioneNicosulfuron + 30 + 1000 + 15 97 88 S-metolachlor + Prosulfuron

Test Example 2

Upland field soil was put into a 1/1,000,000 ha pot, and seeds ofJapanese millet (Echinochloa utilis Ohwi et Yabuno) were sown. On thenext day, predetermined amounts of SC agent containing nicosulfuron asan active ingredient and EC agent containing S-metolachlor as an activeingredient were diluted with water in an amount corresponding to 1,000L/ha and applied for soil treatment by a small sprayer.

On the 27th day after treatment, the state of growth of the Japanesemillet was visually observed to determine the growth inhibition rate.The growth inhibition rate (%) (measured value) and the growthinhibition rate (%) calculated in the same manner as in Test Example 1are shown in Table 2.

TABLE 2 Growth inhibition rate (%) of Japanese millet Compound Dose(g/ha) Measured value Calculated value Nicosulfuron 15 5 — S-metolachlor500 80 — Nicosulfuron + 15 + 500 94 81 S-metolachlor

Test Example 3

Upland field soil was put into a 1/300,000 ha pot, and seeds of wild oat(Avena fatua L.) were sown. On the next day, predetermined amounts of SCagent containing nicosulfuron as an active ingredient, EC agentcontaining S-metolachlor as an active ingredient, SC agent containingterbuthylazine as an active ingredient, SC agent containing mesotrioneas an active ingredient and WG agent containing prosulfuron as an activeingredient were diluted with water in an amount corresponding to 1,000L/ha and applied for soil treatment by a small sprayer.

On the 14th day after treatment, the state of growth of the wild oat wasvisually observed to determine the growth inhibition rate. The growthinhibition rate (%) (measured value) and the growth inhibition rate (%)calculated in the same manner as in Test Example 1 are shown in Table 3.

TABLE 3 Growth inhibition rate (%) of wild oat Compound Dose (g/ha)Measured value Calculated value Nicosulfuron 10 10 — 100 40 —S-metolachlor 250 15 — 2000 60 — Mesotrione 25 0 — 150 5 —Terbuthylazine 250 25 — 1500 5 — Prosulfuron 2.5 25 — 50 0 —Nicosulfuron +  10 + 2000 95 64 S-metolachlor 100 + 250 83 49Nicosulfuron + 10 + 2000 + 25 83 64 S-metolachlor + 10 + 2000 + 150 8566 Mesotrione 100 + 250 + 25 78 49 100 + 250 + 150 85 52 Nicosulfuron +10 + 2000 + 250 93 73 S-metolachlor + 10 + 2000 + 1500 95 66Terbuthylazine 100 + 250 + 250 70 62 100 + 250 + 1500 93 52Nicosulfuron + 10 + 2000 + 2.5 85 73 S-metolachlor + 10 + 2000 + 50 7564 Prosulfuron 100 + 250 + 2.5 90 62 100 + 250 + 50 65 49

Test Example 4

Upland field soil was put into a 1/300,000 ha pot, and seeds ofsunn-hemp (Crotalaria iuncea L.) were sown. On the next day,predetermined amounts of SC agent containing nicosulfuron as an activeingredient, EC agent containing S-metolachlor as an active ingredientand WP agent containing bicyclopyrone as an active ingredient werediluted with water in an amount corresponding to 1,000 L/ha and appliedfor soil treatment by a small sprayer.

On the 28th day after treatment, the state of growth of the sunn-hempwas visually observed to determine the growth inhibition rate. Thegrowth inhibition rate (%) (measured value) and the growth inhibitionrate (%) calculated in the same manner as in Test Example 1 are shown inTable 4.

TABLE 4 Growth inhibition rate (%) of sunn-hemp Compound Dose (g/ha)Measured value Calculated value Nicosulfuron 10 0 — 100 0 —S-metolachlor 250 0 — 2000 0 — Bicyclopyrone 25 0 — 150 20 —Nicosulfuron + 10 + 2000 + 25 25 0 S-metolachlor + 10 + 2000 + 150 83 20Bicyclopyrone 100 + 250 + 25 50 0 100 + 250 + 150 45 20

Test Example 5

Upland field soil was put into a 1/1,000,000 ha pot, and seeds ofsummergrass (Digitaria ciliaris (Retz.) Koel) were sown. When thesummergrass reached 7 to 9-leaf stage, predetermined amounts of ONEHOPENYUZAI (tradename) and Dual Gold (tradename) were diluted with water(corresponding to 300 L/ha) and applied for foliar treatment by a smallsprayer.

On the 14th day after treatment, the state of growth of the summergrasswas visually observed to determine the growth inhibition rate. Thegrowth inhibition rate (%) (measured value) and the growth inhibitionrate (%) calculated in the same manner as in Test Example 1 are shown inTable 5.

TABLE 5 Growth inhibition rate (%) of summergrass Compound Dose (g/ha)Measured value Calculated value Nicosulfuron 15 53 — S-metolachlor 500 0— 2000 0 — Nicosulfuron + 15 + 500  72 53 S-metolachlor 15 + 2000 75 53

As evident from the above Test Example, by mixed use of nicosulfuron andS-metolachlor, a surprising herbicidal activity was exhibited againstgramineae in later leaf stage than in a leaf stage in which the grassescan be controlled by application of the respective compounds alone.

Test Example 6

Upland field soil was put into a 1/1,000,000 ha pot, and rhizomes ofgreen kylling a (Kyllinga brevifolia Rottb. var. leiolepis) havinglowered sensitivity to herbicides were planted. When the height of greenkylling a reached 5 to 7 cm, predetermined amounts of ONEHOPE NYUZAI(tradename) and Dual Gold (tradename) were diluted with water(corresponding to 300 L/ha) and applied for foliar treatment by a smallsprayer.

On the 21st day after treatment, the state of growth of the greenkylling a was visually observed to determine the growth inhibition rate.The growth inhibition rate (%) (measured value) and the growthinhibition rate (%) calculated in the same manner as in Test Example 1are shown in Table 6.

TABLE 6 Growth inhibition rate (%) of green kyllinga Compound Dose(g/ha) Measured value Calculated value Nicosulfuron  30 20 — 100 40 —S-metolachlor 500 15 — 1000  45 — Nicosulfuron +  30 + 1000 65 56S-metolachlor 100 + 500 63 49

As evident from the above Test Example, by mixed use of nicosulfuron andS-metolachlor, a high activity (synergistic effect) was exhibitedagainst weeds having lowered sensitivity to herbicides as compared witha case where the respective compounds were used alone.

Test Example 7

Upland field soil was put into a 1/500,000 ha pot, and on the next day,predetermined amounts of ONEHOPE NYUZAI (tradename) and Dual Gold(tradename) were diluted with water (corresponding to 300 L/ha) andapplied for soil treatment by a small sprayer. On the 14th day aftertreatment, seeds of Japanese bristlegrass (Setaria faberi Herrm) andspotted knotweed, (Polygonum lapathifolium L.) were sown.

On the 21st day after sowing, the state of growth of the Japanesebristlegrass and the spotted knotweed was visually observed todetermined the growth inhibition rate. The growth inhibition rate (%)(measured value) and the growth inhibition rate (%) calculated in thesame manner as in Test Example 1 are shown in Tables 7 and 8.

TABLE 7 Growth inhibition rate (%) of Japanese bristlegrass CompoundDose (g/ha) Measured value Calculated value Nicosulfuron 100 33 —S-metolachlor 250 10 — Nicosulfuron + 100 + 250 90 39 S-metolachlor

TABLE 8 Growth inhibition rate (%) of spotted knotweed Compound Dose(g/ha) Measured value Calculated value Nicosulfuron 30 75 —S-metolachlor 1000 0 — Nicosulfuron + 30 + 1000 90 75 S-metolachlor

As evident from the above Test Example, by mixed use of nicosulfuron andS-metolachlor, a long-lasting remarkable herbicidal activity(improvement in the residual activity) was observed as compared with acase where the respective compounds were used alone.

Test Example 8

Upland field soil was put into a 1/1,000,000 ha pot, and seeds of annualbluegrass (Poa annua L.) having lowered sensitivity to herbicides weresown. When the annual bluegrass reached 5 to 6-leaf stage, predeterminedamounts of ONEHOPE NYUZAI (tradename) and Dual Gold (tradename) werediluted with water (corresponding to 300 L/ha) and applied for foliartreatment by a small sprayer.

On the 14th day after treatment, the stage of growth of the annualbluegrass was visually observed to determined the growth inhibitionrate. The growth inhibition rate (%) (measured value) and the growthinhibition rate (%) calculated in the same manner as in Test Example 1are shown in Table 9.

TABLE 9 Growth inhibition rate (%) of annual bluegrass Compound Dose(g/ha) Measured value Calculated value Nicosulfuron  100 87 —S-metolachlor 1000 18 — 2000 28 — Nicosulfuron + 100 + 1000 94 89S-metolachlor 100 + 2000 99 91

As evident from the above Test Example, by mixed use of nicosulfuron andS-metolachlor, a high activity (synergistic effect) was exhibitedagainst weeds having lowered sensitivity to herbicides, as compared witha case where the respective compounds were used alone.

INDUSTRIAL APPLICABILITY

According to the present invention, a herbicidal composition having awide herbicidal spectrum, having high activity and having a long-lastingeffect can be provided. Further, according to the present invention,broadening of the herbicidal spectrum particularly against gramineae andapplication to genetically-modified crops resistant to ALS inhibitorsare possible, and an increase in the application site can be expected.

Further, in recent years, emergence of weeds which have acquiredresistance due to repeated application of a specific herbicide isproblematic. The present invention can meet requirements by practicalusers that “development of resistance is delayed by use of activeingredients differing in the mechanism in combination”.

The entire disclosure of Japanese Patent Application No. 2011-285654filed on Dec. 27, 2011 including specification, claims and summary isincorporated herein by reference in its entirety.

The invention claimed is:
 1. A herbicidal composition comprising, asactive ingredients, (a) nicosulfuron or its salt, (b) S-metolachlor orits salt, and (c) at least one member selected from the group consistingof (c1) terbuthylazine, and (c2) prosulfuron, and their salts, whereinthe weight ratio of (a) to (b) is within a range of from 1:8 to 1:50,the weight ratio of (a) to (c1) terbuthylazine or its salt is within arange of from 1:2.5 to 1:150, and the weight ratio of (a) to (c2)prosulfuron or its salt is within a range of from 1:0.025 to 1:5.
 2. Theherbicidal composition according to claim 1, wherein the weight ratio of(a) to (b) is within a range of from 1:20 to 1:40, the weight ratio of(a) to (c1) terbuthylazine or its salt is within a range of from 1:8 to1:50, and the weight ratio of (a) to (c2) prosulfuron or its salt iswithin a range of from 1:0.08 to 1:2.
 3. A method for controllingundesired plants or inhibiting their growth, which comprises applying aherbicidally effective amount of (a) nicosulfuron or its salt, aherbicidally effective amount of (b) S-metolachlor or its salt, and aherbicidally effective amount of (c) at least one member selected fromthe group consisting of (c1) terbuthylazine, and (c2) prosulfuron, andtheir salts to the undesired plants or to a place where they grow,wherein (a) is applied in an amount of from 20 to 60 g/ha, and (b) isapplied in an amount of from 500 to 1,200 g/ha, (c1) terbuthylazine orits salt is applied in an amount of from 250 to 1,500 g/ha, and (c2)prosulfuron or its salt is applied in an amount of from 2.5 to 50 g/ha.4. The method according to claim 3, wherein the undesired plants areundesired plants in 7- or later leaf stage.
 5. The method according toclaim 3, wherein the undesired plants are undesired plants havinglowered sensitivity to herbicides.
 6. The method according to claim 4,wherein the undesired plants are plants having lowered sensitivity toALS inhibitors.
 7. The method according to claim 3, wherein theundesired plants are controlled or their growth is inhibited over atleast 60 days after the application of the herbicidally activeingredients.
 8. The method according to claim 3, wherein the undesiredplants are noxious weeds in corn fields.
 9. The method according toclaim 3, wherein (c1) terbuthylazine or its salt is applied in amount offrom 500 to 1,000 g/ha, and (c2) prosulfuron or its salt is applied inan amount of from 5 to 25 g/ha.
 10. The method according to claim 3,wherein the (a) is applied in an amount of from 30 to 40 g/ha, (b) isapplied in an amount of from 800 to 1,200 g/ha, (c1) terbuthylazine orits salt is applied in an amount of from 500 to 1,000 g/ha, and (c2)prosulfuron or its salt is applied in an amount of from 5 to 25 g/ha.11. A method for controlling undesired plants or inhibiting theirgrowth, which comprises applying a herbicidally effective amount of (a)nicosulfuron or its salt, a herbicidally effective amount of (b)S-metolachlor or its salt, and a herbicidally effective amount of (c) atleast one member selected from the group consisting of (c1)terbuthylazine, and (c2) prosulfuron, and their salts, to the undesiredplants or to a place where they grow, wherein the weight ratio of (a) to(b) is within a range of from 1:8 to 1:50, the weight ratio of (a) to(c1) terbuthylazine or its salt is within a range of from 1:2.5 to1:150, the weight ratio of (a) to (c2) prosulfuron or its salt is withina range of from 1:0.025 to 1:5, and the undesired plants are pancium orbrachiaria.